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Date:   Tue, 23 Feb 2021 17:59:18 -0500
To:     Benjamin Coddington <bcodding@redhat.com>
Cc:     Rue Mohr <sn0297@sunshine.net>, linux-nfs@vger.kernel.org
Subject: Re: nfs kernel server bug
Message-ID: <20210223225918.GE8042@fieldses.org>
References: <602020C9.50705@sunshine.net>
 <5B1E0F4D-F26F-4CB5-858A-E49D0819C864@redhat.com>
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From:   bfields@fieldses.org (J. Bruce Fields)
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On Mon, Feb 08, 2021 at 06:58:38AM -0500, Benjamin Coddington wrote:
> On 7 Feb 2021, at 12:18, Rue Mohr wrote:
> 
> >I'm having an issue where the kernel server is dishing out all
> >zeros for file content being read over NFS. The file byte count is
> >correct.
> >Writing files is fine.
> >With the same client, a different server works just fine.
> >
> >I have been trying to pin this down, so far all I know is that the
> >packets from the server actually contain zeros for the file
> >contents.
> >
> >The troubled server kernel is 5.4.1
> >
> >Has anyone encountered this or is it just me?
> 
> Haven't heard of this before, but sounds like a fascinating problem.
> 
> What version of nfs, and what security?  You're seeing READ
> operations returning
> with rsize-ed blocks of all-zero data in a network capture?

It might also be useful to know what filesystem you're exporting, with
what mount and export options.

--b.